#banner {
    width: 1000px;
    height: 1300px;
    margin: 10px auto;
}
#content {
    width: 1000px;
    height: 600px;
    overflow: hidden;
    position: relative;
}
#ul {
    height: 1000px;
    position: absolute;
    left: 0;
}
#ul li {
    list-style: none;
    width: 320px;
    height: 500px;
    float: left;
}
#ul img {
    width: 250px;
    height: 400px;
}
.b {
    width: 50px;
    height: 50px;
    position: absolute;
    cursor: pointer;
}

.b img {
    width: 50px;
    height: 50px;
}

#left {
    top: 300px;
    left: 50px;
}

#right {
    top: 300px;
    right: 50px;
}

#dotul {
    width: 500px;
    position: relative;
    left: 280px;
    top: 560px;
}

#dotul li {
    list-style: none;
    float: left;
    width: 15px;
    height: 15px;
    border-radius: 20px;
    background-color: skyblue;
    margin-left: 20px;
    cursor: pointer;
}

.active {
    background-color: pink !important;
}